A second person has been accused in the abduction of Mint Butterfield, child of Slack and Flickr founders

• Charges were filed in the disappearance of Mint Butterfield, naming a second person.
• Butterfield was found after six days of missing in San Francisco.
• The teen was coerced into running away by two adults, prosecutors say.

A second person is facing charges over the disappearance of Mint Butterfield, the teen child of two tech founders.

Butterfield, 16, went missing for six days before being found alive in the back of a white van in San Francisco's Tenderloin district on Saturday.

Butterfield is the only child of Caterina Fake and Stewart Butterfield, who cofounded Flickr together in 2004. Stewart Butterfield also cofounded Slack and is worth about $1.6 billion, according to Forbes.

The van belonged to Christopher "Kio" Dizefalo, 26, a San Francisco parking valet described as an "adult friend" of Butterfield's in a press release from the Marin County Sheriff's Office.

But later, when Dizefalo was charged, prosecutors named a second person, a woman named Sarah Atkins.

Both were charged with child abduction and the lesser count of contributing to the delinquency of a minor.

Both are due to appear in court on Wednesday morning.

When Butterfield was missing, authorities said they believed the teen went willingly.

(The charge doesn't necessarily contradict that — it's still possible to meet the definition of abduction if the child is willing.)

The sheriff's office also said Dizefalo was arrested in connection with a charge of unlawful sexual intercourse.

It appeared in his inmate record for the Marin County Jail but not as a formal charge in the court records.

Atkins didn't appear as an inmate in jail records.

Dizefalo and Butterfield "had some sort of a quasi-dating relationship," the Marin County Sheriff's Office told The New York Post.

Adam Schermerhorn, a representative for the sheriff's office, told The San Francisco Standard that Atkins was in her late 20s. There's little other information available about her alleged involvement or relationship with Butterfield.

Dizefalo was taken into custody shortly after Butterfield was discovered by police, and his bail was set at $50,000.

Schermerhorn told the Standard that Atkins wasn't there when Butterfield and Dizefalo were found.

Butterfield's parents thanked "family, friends, volunteers and strangers who called in tips and made this recovery possible" in a joint statement obtained by the Standard.

"We especially want to thank the seasoned law enforcement officers who understand the very real threat of predators who use the allure of drugs to groom teenagers," they added.

The Marin County Sheriff's Office didn't immediately respond to a request for further comment on Wednesday, sent outside regular business hours.